Steam-boiler furnace.



No. 656,059. Y Patented Aug. I4, |900. J. THURELL.

STEAM BOILER FURNACE.4

l(Application led Nov. 11, 1899.) (No Model.) 2 Sheets-Sheet 2,

Maf/165.965 l rye/13:07,

JOI-IN THRELL, OF NORTH ADAMS, MASSACHUSETTS.

STEAM-Bonera FURNACE.

SPECIFICATION forming part 0f Letters Patent No. 656,059, dated August14, 1900.

Application filed November l1, 1899- Serial No. 736,683. (No model.)

To all whom it may concern:

Be it known that I, JOHN THURELL, a citizen of the United States,residing at North of Massachusetts, have invented new and usefulImprovementsin Steam-Boiler Furnaces, of which the following is aspecification.

This invention relates to steam-boiler furnaces and grates therefor; andit has for its Object to provide an improved water-grate and grate-frameby means of which the feedwater is directly heated bythe fire and thefurnace-walls and grate-bars are protected from the destructive effectsof the excessive heat to which they are usually subjected insteam-boiler furnaces.

To this end my invention consists in' the features and in theconstruction, combina# tion, and arrangement of partshereinafterdescribed, and particularly pointed out in the claims following thedescription, reference being had to the accompanying drawings, forming apart of this,specilication,wherein Figure 1 is a top plan view of thegrate and grate-frame. Fig.. 2 is a transverse sectional view taken onthe line 2 2 of Fig. 1. Fig. 3 is a similar view taken on the line 3 3of Fig. 1. Fig. 4 is an end View of the furnace and boiler, partlybroken away. Fig. 5 is a vertical sectional view of the hollow doorframe or casing.

Referring to the drawings, the numeral 1 indicates the walls of asteam-boiler furnace, 2 the boiler, and 3 the tire-box.

Built in the front wallv of the furnace is a hollow door frame or casingcomprising ar rectangular frame 4, provided with .laterally-v extendingarms 5, that project horizontally from the opposite ends of therectangular frame and practically form extensions or continuations ofthe bottom thereof. Said rectangular frame and .arms or extensions aremade hollowY--that is to say, are provided with inner and outer Walls 6and '7, forming a water-space 9, through which the water circulates, aswill more fully hereinafter be explained. In the door frame or casingare hinged doors 10, by means of which access may be had to the fire-boxfor stoking, trimmingthelire, andthe like; As shown, the ends ofthe arms5 are built into the side walls of the furnace, and said arms and thebottom of the door-frame rest on a course of brickwork or otherrefractory material of which the furnace-walls are constructed. Adams,in the county of Berkshire and State Arranged at the rear of thefurnace, at approximately the same height as the arms 5, is a cross-beam11, the opposite ends of which are built into the side walls of thefurnace, as most clearly shown in Fig. 2 of the drawings. The arms 5 andcross-beam 11 form su pports for the grate-frame, comprising twoL-shaped hollow casings, each having a short member 12, that rests uponone of the arms 5 and extends from one end of the door frame or casingto the opposite side wall of the furnace, and a relatively-long member13, that rests atits rear end portion in a recess 14, formed in theupper side of the cross-beam 11. It will of course be understood thattwo hollow casings 12 13 are provided, one upon each side of thefire-box, and that the arms 12 thereof, in connection with the hollowdoor-frame and its doors and arms 5, completely close in the fire-box atthe front of the furnace. The hollow side casings are built up closeagainst the side wallsof the furnace or may, if desired, be built intosaid side walls. The hollow casings 1213, as'shown in Figs. 2 and 4,extend up along the entire sides and front of the lire-box, so thatunder no circumstances does the fuel ever come in contact with thefurnace-walls, and the top of the door-casing preferably lies level orflush with the top of the members 12 of the hollow casin gs. Tappedlinto the inner wall of the lower side of the hollow door-casing, asvindicated at 15, Fig. 5, are a plurality of water-tubes 16 17 18 19,

-Which extend longitudinally of the fire-box and at their rear endportions rest in recesses 20, formed inthe upper side of the cross-beam11. The tubes 16 and 19 are connected by elbows 21 to the rear ends ofthe side casings y13,vvhile therear ends of the tubes 17 and 1S Vareconnected together by an elbow 22.' I'Diaphragms or partitions 23 areformed centrally in the upper and lower portions of the hollowdoor-casing, (see Fig. 5,) whereby the waterspace in said casing isdivided into two compartments. A feed-pipe 24C, leading from anysuitable source of watersupply, is tapped into the short member 12 ofoneof the hollow casings, and a pipe25 is in similarmanner tapped intothe opposite member 12 of the IOO other hollow casing and leads to theboiler, as most clearly shown in Fig. l. Removable plugs 2G are insertedin suitable apertures formed in the hollow members 12 opposite the endsof the hollow side members 13, and similar plugs 27 are inserted in thebottom of the hollow door-casing. By removing said plugs the hollow sidecasings and door-frame may be readily cleaned out.

Journaled in suitable bearings (not shown) formed on the side members 13of the gratecasing are two cranked rocker-arms 2S, (sce Fig. 3,) thecranks 29 of which engage notches 30, formed in the under sides of thelongitudinal grate-bars 31. The cranks are formed alternately onopposite sides ofthe rockerarms, so that as said arms are rocked one setof grate-bars will be raised while the alternate grate-bars will belowered in an ordinary and well-known manner. As shown most clearlyinFigs. 1 and 2 of the drawings, agrafebar is set between each twoadjacent watertubes, whereby a water-tube will lie adjacent to each sideof each grate-bar. The rockerarms are coupled toget-hcr bya link 32,which may be reciprocated by any well-known or preferred means forrocking said arms and agitating the grate-bars.

The operation of my improved boiler-furnace will be readily understoodfrom the foregoing description. The water enters by way of the pipe 2iinto the short member 12 of the hollow grate-casing on the left side ofthe furnace, as illustrated in the drawings, then passes down the hollowside member 13, through the elbow 21, and by means of the water-tube 16into the hollow door-casing. From the latter it is deflected by thepartitions 23 into the water-tube 17,thcnce through the elbow 22 intoand through the watertube 18 back into the other side of the hollowdoor-casing, out of the latter through the water-tube 19 and by way ofthe other elbow 2l into the rear end of the hollow side member on-theright of the furnace, through the latter, and enters the boiler throughthe pipe 25. The various passages through which the water passes beforeit reaches the boiler being in direct contact with the fuel and flames,the water by the time it reaches the boiler is raised to anexceedingly-high temperature, ready to be instantly converted intosteam. Moreover, the water-tubes passing between the grate-bars preventthe latter from being burned out, warped, and otherwise damaged, whilethe hollow members 12 and 13, which extend up above the normal height ofthe furnace, prevent the brickwork of the furnace-walls from beingburned out, cracked, and impaired by the excessive heat. In the samemanner the door-casing is prevented from cracking and warping, so thatthe furnaeedoors will at all times properly fit the casing, whereby thedrafts can be properly controlled. By the means described the water iscompelled to traverse a very long heating circuit before it reaches theboiler, thus insuring its being raised to a very high temperature beforeit reaches the boiler irrespective of how low the fu rnacedire may be,while at the same time the grate-bars and furnacewalls and thedoor-casing are elfectually protected from the injurous effects of theexcessive heat necessarily maintained in steamboiler furnaces. Byconnecting the watertubes in the manner described they may be veryreadily taken apart for cleaning and without disturbing any of the otherparts, and in like manner the gratebars may be easily removed forremoving the clinkers therefrom and for other purposes.

In practice a curved metallic shield 33 is supported above the elbows 2land 22 at the rear of the furnace and acts as a protection for thelatter. Said shield is perforated, as at 33, to permit the furnace-gaseswhich are apt to accumulate at the back of the furnace to ascend and mixwith the products of combustion that arise from the burning fuel.

Having described my invention, what I claim is- 1. Inaboiler-furnace,the combination with a grate-frame comprising two hollow casingssupported on opposite sides of the fire-box and extending up the innersides of the latter above the normal level of the fuel, said hollowcasings at their front ends being formed with right-angled hollowextensions built into the front wall of the furnace, a return-bendconduit connecting the rear ends of said hollow side casings anddisposed horizontally in the bottom of the lire-box, a water-inletleading into one of said hollow extensions, and a water-outlet leadingfrom the other hollow extension into the boiler, substantially asdescribed.

2. In a boiler-furnace, the combination with a grate-frame comprisingtwo hollow casings supported on opposite sides of the fire-box andextending up the inner sides of the .lat ter above the normal level ofthe fuel, of grate-bars supported in the lower portion of said hollowgrate-frame,watertubes arranged between the grate-bars and connectingthe rear ends of said hollow casings, a water-inlet connectedto thefront end of one of said hollow casings and a water-outlet connected tothe other hollow casing, substantially as described.

3. In a boiler-furnace, the combination with a grate-frame comprisingtwo hollow casings supported on opposite sides of the nre-box andextending up the inner sides of the llatter above the normal level ofthe fuel, of longitudinal grate-bars supported in the lower portion ofsaid hollow grate-frame, watertubes arranged between the grate-bars,elbows connecting the rear ends of the outermost water-tubes to the rearends of the hollow side casings, means for connecting together the rearends of the intermediate wa ter-tubes, a hollow casing connectingtogether the front ends of the Water-tubes, a waterA inlet connected tot-he front end of one of said IIO hollow casings and a water-outletconnected to the front end of the other hollow casing, substantially asdescribed.

4. In aboiler-furnace, the combination with a grate-frame comprising twohollow casings supported on opposite sides of the fire-box and extendingup-the inner sides of the latter above the normal level of the fuel, oflongitudinal grate-bars supported in the lower portion of said hollowgrate-frame, watertubes arranged between the grate-bars and alternatelyconnected together at their opposite ends, the rear ends of the twooutermost of said water-tubes being respectively connected to the rearends of the hollow casings, a water-inlet connected to the front end ofone of said hollow casings and a water-outlet connected to the front endof the other hollow casing, substantially as described.

5. In a boiler-furnace, the combination with a grate-frame comprisingtwo hollow casings supported on opposite sides of the re-box, oflongitudinal grate-bars supported in the lower portion of said hollowgrate frame, watertubes arranged between the grate-bars, elbowsconnecting the rear ends of the two outermost water-tubes to the rearends 'of the hollow side casings, means for connecting together the rearends of the intermediate water-tubes, a hollow casin g connectingtogether the front ends of the water-tubes, a water inlet and outletconnected respectively to the front ends of the two hollow side casings,and an arched perforated shield supported over the rear connections ofthe water-tubes, substantially as described.

6. In a boiler-furnace, the combination with a grate-frame comprisingtwo hollow casings supported at the opposite sides of the fire-box andformed at their front ends with right-angled hollow extensions builtintothe front wall of the furnace, of a hollow door-casing fitted betweensaid hollow extensions, longitudinal grate-bars supported in the lowerportion of the grate-frame, water-tubes arranged between the grate-bars,said water-tubes communicating at their front ends with the hollowdoor-casing, elbows connecting the rear ends of the two outermost of thewater-tubes with the rear ends of the hollow casings, means forconnecting the rear ends of the intermediate water-tubes, and waterinlets and outlets respectively connected to the said hollow extensions,substantially as described.

7. In a steam-boiler furnace the combination with the hollow door-casingprovided with lateral arms supported at their ends in the sides of thefurnace-walls, of the grateframe comprising two hollow casings disposedin the opposite sides of the fire-box and formed at their front endswith right-angled hollow extensions supported on said lateral armsbetween the ends of the door-casing and the side walls of the furnace, across-beam tted at its opposite ends in the side walls at the rear ofthe furnace and supporting the rear ends of the hollow side casings,grate-bars supported in the bottom of the grate-frame, water-tubesdisposed between the grate-bars, said water-tubes at their front endsbeing connected with the hollow door-casing and alternately connectedtogether at their rear ends, the ends of the outermost of saidwatertubes being connected respectively to the rear ends of the hollowside casings, substantially as described.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

JOHN THURELL.

Witnesses:

MILTON L. FIRO, ARcHIE GUILBo.

